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Nikon D800 50 mm Lens (Sensor Artifact) in M94 Area Star Field, 



    
        

            jerryyyyy
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Nikon D800 50 mm Lens (Sensor Artifact) in M94 Area Star Field

Getting plate-solving status, please wait...
Nikon D800 50 mm Lens (Sensor Artifact) in M94 Area Star Field, 



    
        

            jerryyyyy
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Nikon D800 50 mm Lens (Sensor Artifact) in M94 Area Star Field

Imaging cameras: NIKON D800

Guiding cameras: SBIG STT 8300M


Dates:May 24, 2020

Frames: 68x60" (1h 8') ISO400

Integration: 1h 8'

Avg. Moon age: 1.67 days

Avg. Moon phase: 3.12%


Astrometry.net job: 3569295

RA center: 13h 2' 4"

DEC center: +39° 50' 12"

Pixel scale: 118.689 arcsec/pixel

Orientation: 94.457 degrees

Field radius: 23.337 degrees


Resolution: 1218x813

Locations: Stanford Faculty Observatory (Bortle 6 SQM 18.6), Stanford, California, United States

Data source: Own remote observatory

Remote source: Non-commercial independent facility

Description

Nikon hacker firmware used to get true levels from the sensor, which seems to have a small defect in the chip field that internal processing masked... this is seen in the last revision, which I just put up with the red arrows. If you do not get linear levels, you cannot get a good flat field.

The original image, which is better than my previous ones with the Nikon, has stopped down the 50mm F 1.4 to F 2.8 to reduce vignetting and star distortions.

Both were improved and flat field corrected... flats are not yet perfect either There are still stars distortions, but probably will be good for H-alpha when I get the filter. I have the Astronomiks 12nm ordered to do Sharpless2 wide fields.

Processing:

Stacked in PI with default settings.

Photometrically color corrected.

DBE applied to get rid of gradients but no new STF used.

Converted to non-linear and denoised in Photoshop with Topaz Denoised.

Background clipped.

Result about 18000 stars. Original before denoising had 19000. Cliped 1000 stars to deal with the chip defect.

Comments

Revisions

  • Nikon D800 50 mm Lens (Sensor Artifact) in M94 Area Star Field, 



    
        

            jerryyyyy
    Original
  • Final
    Nikon D800 50 mm Lens (Sensor Artifact) in M94 Area Star Field, 



    
        

            jerryyyyy
    B

B

Description: Sensor defect... left and right halves of the sensor are different... line down the middle with the red arrows.

Uploaded: ...

Sky plot

Sky plot

Histogram

Nikon D800 50 mm Lens (Sensor Artifact) in M94 Area Star Field, 



    
        

            jerryyyyy

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